The Advertising Standards Authority has rejected a complaint by Fluoride Free Hamilton about a pro-fluoridation advertisement the anti-fluoride group likened to propaganda.
The advertisement was placed in the Waikato Times by the Ministry of Health and Waikato District Health Board in late September.
It showed a family holding a billboard that said: "I vote for fluoride being added to water."
It also stated that fluoride "makes a huge difference in reducing tooth decay, particularly for children", "is safe", and "provides an affordable benefit to everyone".
Fluoride Free Hamilton co-ordinator Pat McNair laid a complaint with the authority claiming all three of the statements in the advertisement were false.
"The ad was designed to mislead the public prior to a referendum by way of propaganda," she said in her objection.
The complaints board examined each of the statements highlighted by Mrs McNair, along with responses from the Waikato District Health Board and Ministry of Health.
It ruled all three statements had been substantiated, none would deceive or mislead consumers and the advertisement had "observed the requisite standard of social responsibility".
In the decision, the board said the advertisement was clearly advocacy promoting the benefits of water fluoridation, and it identified the advertisers and gave their contact details.
It also noted the DHB had "a duty to provide information to the public", and would be seen as an expert in the area due to its role.
But Mrs McNair told the Times she stood by her complaint that it was "factually incorrect and intentionally misleading", and she found the complaints system "flawed".
"By its own admission (although the ASA is theoretically an independent body) it cannot rule against another Government authority if they are broadly considered to be 'experts' in the field and the ASA has been publicly warned to 'tread carefully' in this area," she said.
However, she said it upheld the group's previous complaint - made by Ken Evans from Tauranga about an advertisement placed by a group of dentists.
"As this was not a complaint against a government authority, the ASA were free to rule that this claim could not be substantiated. So obviously the ASA complaints system is flawed."
But the dismissal of Mrs McNair's complaint was a good outcome for DHB with communications director Mary Anne Gill, who prepared the District Health Board's response, saying she was pleased.
The authority found they showed a "due sense of social responsibility to consumers and to society" when preparing the advertisement.